How to Make Industrial-Style Geo Cement Coasters
Call it cement, plaster or concrete. It's grey, strong, stiff and can take just about any form! You can mostly find it decorating lofts and urban apartments for a minimalist and industrial look. This common construction material is becoming a huge design and interiors trend and I love working with it. In this tutorial I'm making geometric coasters. They are very stable, super-practical and will make a great piece of design for your home.
- About 600 grams rapid drying cement plaster
- Two jewelry boxes 8cm x 8cm (3.5 x 3.5in)
- Clear tape (two sizes)
- Mixing container
- Little wooden blocks
- Sand paper
- Paint brushes
- Palette knife
- Painting palette tray
- Acrylic paints
1. Reinforce the Boxes
In this tutorial, I'm using jewelry boxes as molds. They need to be prepared before you can add wet ingredients, as the moisture can warp the cardboard and destroy your design. To avoid this, use the narrow tape to cover and secure the four sides of the box in place. Pull the tape from edge to edge and when it is tight enough, stick it down. Go around more than once.
Now use the wide tape to cover the bottom and the edges of the box parts. Make sure that the box is well covered, except the inner part.
2. Prepare the Mixture
Place the cement powder in a plastic container. Pour some water and stir it up with the back of your paintbrush. For 600 grams of powder I used about 350ml of water. You can buy cement powder from your local hardware or craft store. Just make sure you follow the manufacturer's advice regarding how much water to add to the mix. If you accidentally put in too much water, just add some more powder.
Keep stirring until the mixture is wet. The desired texture looks a lot like yoghurt. Make sure you work quickly. Rapid drying cement starts to dry and set in about 10 to 15 minutes.
3. Fill the Molds
Pour the mixture in to the boxes. For chunky-style coasters, fill the boxes right up to the top with the cement mixture. If you'd like to make thinner coasters, pour in less mixture, but keep in mind that you'll be sanding them back. So don't make them any thinner than 0.5cm.
Smooth the surface of the mixture using the palette knife and make sure all the corners are evenly filled.
4. Make a Design
Now it's time to improvise and be creative! Use the blocks to create recesses on the surface of your coasters. Push the wooden block gently in the mixture, but be careful not to reach the bottom. You only need to push it down by a few millimeters to create a 3D effect. I made a square recessed design in the corner of each coaster.
This is the tricky part! After five minutes, pull the blocks gently out of the mixture and then insert them back into the same position. Repeat every five minutes to avoid the block getting stuck in the cement.
Make sure you are pulling upwards and avoid moving right or left. You can help the block move by inserting the palette knife in the four sides, just like you would do after baking a cake.
About 20 to 30 minutes after pouring the mixture into the molds, the surface should feel dry and solid (this time varies according to different manufacturers). Cut the edges of the paper box and take the coaster out. If the paper is stuck to the cement, rub it with your fingers under running water. The paper will melt and fall off. Leave the coasters to dry.
5. Add the Finishing Touches
Use two different sandpapers to sand back the surface of the coaster. A medium one will remove all the bumps and lumps, making the surface even. Follow with a finer sandpaper to make the surface smooth and remove scratches.
At this stage the coasters look dry but they are still fairly moist inside. This is helpful because it makes the cement soft to work with, and you'll avoid dust. You can also tidy up the shape and design with a normal cutter.
Use the big brush to clean any dust from sanding.
Mix acrylic paints and carefully paint the little squares in your favorite colors to create depth and a 3D effect. You can use one color or a different one for each coaster. This is a great idea to avoid mixing glasses at a party.
Enjoy a Cold Drink!
Your brand new coasters are ready! It's time to call your friends for a cocktail night or maybe package them together as a cool gift for a friend.
In this tutorial you learned how to mix and pour cement into a prepared mold, and stamp the surface with a block to give it a 3D geometric design. You also learned how to give the coasters a nice finish, with different levels of sanding, brushing and painting.
Do you like industrial-style cement design? How did you find this tutorial? Let us know in the comments section below – we’d love to hear from you and even see your version of this tutorial.